Rock salt prism does not absorb ……………… radiation.

Options

A. IR
B. UV
C. microwave
D. radiowave

Explanation

To solve the question "Rock salt prism does not absorb ……………… radiation," we need to analyze the properties of rock salt prisms in relation to different types of radiation.

### Step-by-Step Solution:

1. **Understand the Properties of Rock Salt Prism**:
- Rock salt prisms are known for their optical properties. They are used in various applications, especially in the infrared region of the electromagnetic spectrum.

2. **Identify the Types of Radiation**:
- The question provides four options: infrared, ultraviolet, microwave, and radio wave. We need to determine which type of radiation is not absorbed by rock salt prisms.

3. **Analyze Each Option**:
- **Infrared Radiation**: Rock salt prisms are specifically designed to transmit infrared radiation, meaning they do not absorb it.
- **Ultraviolet Radiation**: Generally, rock salt can absorb UV radiation, so this option is incorrect.
- **Microwave Radiation**: Rock salt does not have a specific property that allows it to transmit microwaves effectively, but it is not primarily known for this.
- **Radio Wave Radiation**: Rock salt can interact with radio waves, but it is not commonly used for this purpose.

4. **Conclusion**:
- Since rock salt prisms are used to produce and transmit infrared radiation without absorption, the correct answer to the question is "infrared radiation."

### Final Answer:
Rock salt prism does not absorb **infrared radiation**.

---